Job categorization is a necessary step in the process of hiring new employees. In the employment office of most corporations, as resumes are received they are sorted and the applicant is assigned a job skill code indicating the types of jobs which the applicant may be able to perform. At present, this process requires someone who can read the resume and categorize the applicant.
The categorization process now used requires a skilled professional recruiter to read the resume. The recruiter uses his experience and knowledge to classify the applicant into one or several job categories. The knowledge required to perform the classification includes knowing which skills are required to perform various jobs, understanding the corporate job structure, and identifying an applicant's strengths and weaknesses.
The knowledge of which skills are required for a particular job category is acquired by professional recruiters over a number of years. Typically, a recruiter starts by working in a particular job area and reviews resumes which have already been sorted by a more experienced recruiter. This process allows the recruiter to gain experience. After a period of time the recruiter becomes familiar with the contents of applicants' resumes in this particular job category and can distinguish resumes falling within this job category from those more applicable to other categories.
In addition to knowing the necessary job skills, the recruiter must understand the job structure or organizational chart of both his own and other companies. In categorizing applicants an experienced recruiter makes frequent use of the job titles held by the applicant which can indicate the applicant's previous positions.
A recruiter should also be able to identify the strengths and weaknesses of an applicant. Although the resume may indicate a very wide range of skills, the applicant may be proficient in only a small subset of these skills. A skilled recruiter is able to identify which skills are accurate descriptions of the applicant's talent and which are just "fluff" to inflate the applicant's resume.
Computer programs which attempt to simulate human knowledge and understanding are called knowledge-based systems. In particular, those which simulate an expert's knowledge in a particular domain are called expert systems. An expert system capable of performing job categorization would simulate the categorization skills of an experienced recruiter. General techniques used in creating expert systems include using rules which embody the expert's procedural knowledge (rule-based systems), using data structures containing the data known by the expert (frame-based systems), and using probabilistic methods to simulate expert judgement (evidential reasoning systems).
Rule-based systems are very effective if the expert's knowledge can be expressed in terms of logical relations of "IF-THEN" rules. An example of an IF-THEN rule is given below: